another fix

src/gamepad.cpp

@@ -17,7 +17,7 @@ Gamepad::Gamepad(uint8_t latch, uint8_t clock, uint8_t data)
     pinMode(data, INPUT);
 }
 
-uint16_t Gamepad::getState() const
+uint16_t Gamepad::getState()
 {
     return this->readCon();
 }